As a background technology related to the present technical field, there is a flow sensor module described in Japanese Patent Application Laid-Open No. 2012-112979 (PTL 1).
PTL 1 describes “a surface of a semiconductor chip CHP1, a wire W1, a lead RD1, a wire W2, an entire principal plane of a semiconductor chip CHP2, and a part of a wire W3 and a lead RD2 excluding a flow detection portion FDU and its vicinity are sealed with a resin MR”. Further, “a lead frame LF on which the semiconductor chip CHP1 and the semiconductor chip CHP2 are mounted is sandwiched by the upper mold UM and the lower mold BM through a first space” (see paragraph 0142 and FIG. 18).
Further, PTL 1 describes “a structure in which a part of an upper portion of the semiconductor chip CHP1 is not covered with the resin MR in a cross section of a gas (air) in a flowing direction by making a dimension LR1 of a tip of an insert IPU installed on the upper mold UM larger than a dimension LC1 of the semiconductor chip CHP1” (see paragraph 0279 and FIG. 45).